Placement Table Sensor Recess for Thermal Accuracy

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Solution Overview

Problem

In semiconductor device testing, a significant difference between the actual temperature of the device and the measured temperature occurs due to varying thermal resistance distances from the temperature sensor, especially in placement tables with a single sensor, leading to inaccurate temperature readings and potential structural weakness when multiple sensors are added.

Innovation Solution

A placement table design with a recessed portion on its surface to house multiple temperature sensors, including transistors and a central platinum resistance sensor, reduces thermal resistance distance and maintains structural integrity by minimizing the number of insertion holes needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a single temperature sensor is used in the placement table, then the structural strength is maintained, but the temperature measurement accuracy deteriorates due to varying thermal resistance distances

Engineering Contradiction:
Improvestructural strengthVSAvoidtemperature measurement accuracy
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

The placement table is divided into multiple regions, each equipped with its own temperature sensor. This segmentation allows temperature measurement at multiple locations simultaneously, reducing the impact of thermal resistance variations and improving overall measurement accuracy while maintaining structural integrity through distributed sensing points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Temperature sensors are strategically positioned at specific locations on the placement table where temperature measurement is most critical. This local quality approach ensures that areas with varying thermal resistance have appropriate sensing coverage, improving measurement precision without requiring sensors throughout the entire structure.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If multiple temperature sensors are added to reduce thermal resistance distance, then temperature measurement accuracy improves, but the structural strength deteriorates due to multiple insertion holes

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidstructural strength
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

Temperature sensors are arranged in a planar distribution pattern on the surface of the placement table rather than concentrating them in one location. This two-dimensional arrangement reduces the thermal resistance distance from multiple measurement points to various regions of the device under test, improving accuracy while the sensors are mounted on the surface without requiring deep insertion holes that would compromise structural strength.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If temperature sensors are positioned closer to the device under test, then the temperature measurement accuracy improves, but the device complexity increases

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidplacement table structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The placement table structure is designed to serve multiple functions: it provides mechanical support for the device under test, facilitates temperature control, and incorporates temperature sensing capabilities. By integrating temperature sensors into the existing placement table structure rather than adding separate mounting mechanisms, the design achieves improved measurement accuracy without significantly increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design effectively reduces the temperature measurement discrepancy and preserves the structural strength of the placement table by dispersing temperature sensors across the surface, ensuring accurate temperature readings and maintaining the table's yield strength.

Implementation Method 1

a temperature sensor that measures a temperature of the semiconductor device

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3992645B1Placement table, testing device, and testing method
Publication Date: 2024.08.07 TOKYO ELECTRON LTD
  • EP3992645B1 patent drawingFigure 1
  • EP3992645B1 patent drawingFigure 2
  • EP3992645B1 patent drawingFigure 3

AI summary

There is provided a placement table having an upper surface on which a device to be processed is placed. The placement table comprises: a top plate having a placement surface for the device; a heating unit configured to heat the top plate; a plurality of temperature sensors configured to acquire temperature of the top plate at desired measurement positions in a plan view; and a positioning unit electrically connected to the temperature sensors and configured to position the temperature sensors at the measurement positions in a plan view. The positioning unit is formed of a flexible substrate having flexibility.